1. Field of the Invention
The present invention relates apparatus for separating liquids and solids, e.g. from a mixture of biological waste material or sludge and water.
More particularly, the present invention is useful, for example, in the treatment of biological waste and sludge by dewatering and composing to form fertilizer, and in the conversion of waste water into usable water or even into drinking water, and may be employed in the treatment of waste in waste treatment plants, from municipal sewerage systems, industrial sewage treatment plants, and other sources of human and animal waste, for example slaughter houses, hospitals and other buildings, greenhouses and other agricultural installations. The present apparatus may be connected to or separate from sewers and is useful both in fixed installations and in mobile waste treatment apparatus.
2. Description of the Prior Art
For the separation of solids from liquids, it is known to employ a cylindrical screen or basket formed of a plurality of circular bars which are spaced apart axially of the screen and which extend around an auger which is coaxial with the screen and which extends upwardly, at an inclination from the screen, for conveying separated solids from the screen. The auger is provided in an upwardly-open semi-cylindrical trough. The incoming mixture of liquid and solid material flows into the cylindrical screen through a lower, open end of the screen, and the liquid then flows outwardly from the screen between the circular bars, so that the solid material in retained on the interior of the screen. The screen is rotated periodically to raise the solid material over the auger, into which the solid material drops, or a rake is rotated around the interior of the screen to collect and raise the solid material so that it can then be deposited in the auger. One such apparatus is disclosed in U.S. Pat. No. 5,110,461, issued May 5, 1992 to the present inventor.